Fluid-pressure brake.



W. V. TURNER.

FLUID PRESSURE BRAKE.

APPLICATION FILED JULY 29. 1913.

l 1 92,960. Patented Aug. 1, 1916.

INVENTOR W. V. TURNER.

FLUID PRESSURE BRAKE.

APPLlCATl-ON FILED JULY 29, 1913.

1 1 92,960. Patented Aug. 1, 1916.

5 SHEETS-SHEET 2.

46 To sclviea K55.

7-0 .404. A'sv TO EMEIC a. C

WITNESSES (g INVENTOR W. V. TURNER.

FLUID PRESSURE BRAKE.

APPLICATION FILED JULY 29, ms.

1,192,960. Patented Aug. 1, 1916.

5 SHEETS-SHEET 3- WITNESSES INVENTQR W. V. TURNER.

FLUID PRESSURE BRAKE.

APPLICATION FILED IULY29. 1913.

1,192,960. Patented Aug. 1, 1916.

5 SHEETS-SHEET 4.

WITNESSES INVENTOR W. V. TURNER.

FLUID PRESSURE BRAKE.

APPLICATION FILED 1uLv29. 1913.

1 1 92,960. Patented Aug. 1, 1916.

5 SHEETS-$HEET 5.

WITN INVENTOR STATES PATENT OFFICE.

WALTER V. TURNER, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEAIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

FLUID-PRESSURE BRAKE.

Specification of Letters Patent.

Patented Aug. 1, 1916.

To all whom it may concern lie it known that I, VVAL'rnn V. TURNER, acitizen of the United States, residing at Edgewood, in the county ofAllegheny and State of Pennsylvania, have invented new and usefulImprovements in Fluid-Pressure Brakes, of which the following is aspecification.

This invention relates to fluid pressure brakes, and more particularlyto a brake controlling valve mechanism.

In applying and releasing the brakes on railway trains, it is highlydesirable to provide a brake controlling valve mechanism which has amaximum sensitiveness to release and a minimum sensitiveness toapplying, so that the brakes may be readily released on long trainsunder a comparatively slow increase in train pipe pressure and at thesame time are prevented from applying under inevitable fluctuations intrain pipe pressure such as occasioned, for example, by variationsbetween the opening and closing pressures in the operation of the trainpipe feed valve, and furthermore, where the apparatus is designed toprovide graduated release, it is desirable that the controlling valveparts respond with facility to light increases in train pipe pressure.

One object of my invention is therefore to provide an. improved brakecontrolling valve mechanism which has a minimum sensitiveness tomovement in applying the brakes and a maximum sensitiveness in releasingthe brakes.

Another object of my inventionis to provide a brake controlling valvemechanism having a minimum sensitiveness to movement from a normal brakerelease position and ha ving another release position in which thecontrolling valve parts have a maximum sensitiveness to movement. Theequalizing portion of a controlling valve device has amain slide valveand an auxiliary graduating valve having a movement relative to the mainvalve, and while ordinarily, as intended, the graduating valve willinitially move relatively to the main valve in applying the brakes, itmay sometimes happen that the graduating valve will stick so that bothvalves move together. When this occurs, the brake applying ports may notbe properly opened, so that an application of the brakes may not besecured.

Another object of my invention is to pro vide an equalizing valve devicehaving a main valve and a graduating valve and adapted. to effect anapplication. of the brakes when the graduating valve fails to moverelatively to the main valve.

Another object of my invention is to provide an improved valve mechanismfor effecting an emergency application of the brakes which has a maximumsensitiveness to a sudden rate of reduction in train pipe pressure.

Another object of my invention is to provide an improved emergencycontrolling valve mechanism responsive to a predetermined reduction intrain pipe pressure and also having a high degree of sensitiveness to asudden rate of deduction in train pipe pressure.

In the accompanying drawings; Figure 1 is a diagrammatic view of a carair brake equipment with my improvements applied thereto; Fig. 2 acentral sectional diagrammatic view of a valve mechanism for controllingthe application and release of the brakes embodying my invention andshowing the parts in the normal release position; Fig. 3 a view similarto Fig. 2, showing the parts in service application position; Fig. 4 asimilar view, showing the parts in emergency application position; Fig.5 a similar view with the emergency portion broken away, showing theparts in graduated release position; Fig. (l a view similar to 5,showing the parts in graduated release lap position: and Fig. 7 asectional view of the graduated release cap in the position for cuttingout graduated release.

As shown in Fig. 1 of the drawings, the car air brake equipment maycomprise a train pipe 1 connected to the brake control ling valvemechanism 2, a service brake cylinder 3 connected by pipe 1 and anemergency brake cylinder 0 connected by pipe 6 to the valve mechanism 2,an auxiliary reservoir 7 service reservoir 8, and emergency reservoir 9connected to said valve mechanism by the respective pipes 10, 11, and12.

In Figs. 2 to 6 inclusive is shown a brake controlling valve mechanismembodying my invention and comprising an equalizing portion having apiston chamber 13 connected to passage 14 leading to train pipe 1 andcontaining an equalizing piston 15. A valve chamber 16 on the oppositeside of piston 15 is connected by a passage 17 with auxiliary reservoirpipe 10 and contains a main slide valve 18 and a graduating slide valve19 mounted on the main slide valve and having a movement relativethereto.

The equalizing valve device controls ports for supplying fluid to thebrake cylinder and ports for varying the pressure on a separate releasevalve device comprising a double headed piston having piston heads 20and 21 and a slide valve 22 operated by said piston. Chamber 23 at theouter face of piston head 20 communicates with a passage 24 leading tothe seat of slide valve 18 and chamber 25 at the outer face of pistonhead 21 communicates with a passage 26 also leading to the seat of mainslide valve 18. Valve chamber 27 intermediate the piston heads 20 and 21is in open communication with passage 28 connected to passage 29 whichleads to emergency reservoir pipe 12.

A charging valy'e device 30 is preferably employed for preventing therecharging of the large ser vice reservoir 8 until the auxiliaryreservoir 7 and emergency reservoir 9 have been recharged to within afew pounds, for example, five pounds, of the normal pressure carried.

The above mentioned charging valve device comprises differential pistonheads 31 and 32, the chamber 33 at the outer face of piston head 31being connected by passage 34 to auxiliary reservoir passage 17 andchamber 35 at the outer face of piston head 32 being connected bypassages 36 and 37 with a port 38 in the release position of the releaseslide valve 22.

In the upper position of the charging valve device 30, the spaceintermediate the piston heads 31 and 32 establishes communication frompassage 37 to a passage 39, through which the service reservoir 8 isrecharged.

For controlling emergency applications of the brakes. an emergency valvemechanism is provided comprising a piston 40 contained in piston chamber41 and a slide valve 42 and auxiliary slide valve 43 contained in valvechamber 44. The valve chamber 44 is connected to a quick action chamber45 by passage 46 and piston chamber 41 is connected to passage 47controlled by protection valve device 48. An emergency quick actionvalve device is also pro vided comprising a piston 49 having chamber-50at its outer face communicating with passage 51 leading to the seat ofemergency slide valve 42 and a valve 52 operated by said piston 49 foropening communication from passage 53 leading to train pipe passage 54to an atmospheric exhaust port 55.

The release position of the equalizing valve device is determined by apiston stop device 56 having a central stem 57 adapted to engage the endof the main slide valve 18. The piston stop device 56 has a chamber 58at one side which communicates with a passage 59 leading to emergencyreservoir passage 28 and the opposite side of the piston device is opento the valve chamber 16. The piston device is adapted to seat in itsopposite extreme positions and a spring 60 assists the fluid pressure invalve chamber 16 in holding the piston stop device at its outer seat.

In operation, when fluid under pressure is supplied to the train pipe 1,fluid flows through passages 54 and 14 to piston chamber 13, forcing theequalizing piston 15 to full release position, and through feed groove61 around piston 15 to valve chamber 16. From "alve chamber 16 fluidflows through passage 17 and charges the auxiliary reservoir and alsothrough passage 62 branching from passage 17, when the graduated releasecap 63 is in the position shown in Fig. 2, to port 64 in the releaseslide valve 22. thus charging the valve chamber 27.

The emergency reservoir 9 is charged through passage 112 past chargingcheck valve 113 to valve chamber 27 and thence through passage 28 to theemergency reservoir 9, and the service reservoir 8 is charged throughport 38, passage 37 around the charging valve 30 to passage 39 andthence, when the release valve device is in release position throughcavity 65 and passages 66, 67 and 68 to service reservoir pipe 11. Fluidfrom the train pipe also flows through passage 54 to the protectionvalve device 48 and when the train pipe pressure exceeds a predetermineddegree. the protection "alve device is shifted to the position shown inFig. 2 of the drawings, so that communication is opened from passage 54to passage 47 leading to emergency piston chamber 41. Fluid then flowsthrough feed groove 69 around the emergency piston 40 and charges valvechamber 44 and also quick action chamber 45. Quick action closingchamber 70 is charged from valve chamber 44 through passage 71.

In the normal release position of the equalizing valve device, passage24 is blanked, so that fluid pressure equalizes through an equalizingport 72 in the piston head 20 from valve chamber 27 of the release valvedevice into piston chamber 23. Passage 26 leading to piston chamber 25is connected to an atmospheric exhaust port 73 through port 74, cavity75 in graduating valve 19 and port 76 and cavity 77 in the main slidevalve 18. As fluid pressure in piston chamber 23 opposes atmosphericpressure in piston chamber 25, the release valve device is shifted torelease position. as shown in Fig. 2 of the drawings. The piston head 21is also provided with an equalizing port 78, but as the piston head 21is adapted to seat around the port opening of passage 26,

escape of fluid from valve chamber 27 to the atmosphere is prevented.

In the release position of the release valve device, the service brakecylinder 3 is connected to the service brake cylinder exhaust port 79through pipe 4, passages 80 and 81, and cavity 82 in the release slidevalve 22.

In order to effect a service application of the brakes, the train pipepressure is reduced and thereby the equalizing valve parts are shiftedto application position, as shown in Fig. 3 of the drawings. The firstmovement of the equalizing piston 15 toward service application positioncloses the feed groove 61 and the emergency reservoir charging port 112and connects a resistance increasing cavity 109 with the atmospherethrough port 110, port 111 and cavity 75 in the graduating valve 19, andport 7 6 to exhaust port 73. The employment of the resistance increasingcavity insures that very light train pipe reductions, say below fivepounds, will not be suilicient to move the slide valve and cause a brakeapplication.

In this position, service port 83 is brought into register with passage84 and is uncovered by the movement of the graduating valve 19. Fluidthen flows from valve chamber 16 through passage 84, past check valve 85to passage 81 and thence to the service brake cylinder 3. In serviceapplication position, the passage 26 is blanked by the main slide valve18, while passage 24: is connected to exhaust port 73 through cavity 77sothat the fluid pressure previously equalized into that portion ofpiston chamber 25 which is outside of its seat operates to shift therelease valve device so as to close the brake cylinder exhaust, as shownin Fig. 3. The piston head 20 is adapted to seat around theport openingof passage 24, so that escape of fluid under pressure from valve chamber27 to the atmosphere is prevented. IVhen the equalizing valve device isin full application position, the service reservoir passage 67 isuncovered by the main slide valve 18, so that fluid is supplied fromboth the auxiliary reservoir and the service reservoir in making serviceapplications. The principal purpose of dividing the supply for serviceapplications into twogvolumes is to provide a small reservoir volumeopen to the valve chamber 16 in release position, so that in graduatingthe release of the brakes,

the graduated release reservoir has only a small volume to equalizeinto, thereby providing a very flexible graduated release with a minimumemergency reservoir volume, as the graduated release feature iscontrolled by the expansion of emergency reservoir air into theauxiliary reservoir volume and this arrangement also provides a smallervolume for the emergency reservoir to equalize into. 'In making aservice application of the brakes, as chamber 58 at the outer face ofpiston 56 is constantlv open through passage 59 to emergency reservoirpressure, it will be seen that the reduction in auxiliary reservoirpressure on the oppositc'side of the piston by flow to the brakecylinder permits the higher emergency reservoir pressure to shift thepiston 56 to its inner seat, as shown in Fig. 3 of the drawings.

If a graduated release of the brakes is desired, a gradual increase intrain pipe pressure is made and the equalizing valve device isthereuponmoved inwardly until the main slide valve 18 strikes the stem57. In this position, as shown in Fig. 5, a foot extension of port74-registers with passage 26 and cavity 77 registers with exhaust port73, While ports 74 and 76 are connected by caw ity 75 in the graduatingvalve 19. Fluid under pressure is therefore vented from release pistonchamber 25 and as passage 24 leading to release piston chamber 23 isblanked, the fluid pressure in chamber 23 operates to shift the releasevalve device to release position, so that the brake cylinder isconnected with exhaust port 79.

In the release position. of the release slide valve 22, port 64registers with passage (32, so that fluid at emergency reservoirpressure is supplied from valve chamber 27 to equalizing valve chamber16. Upon an increase in pressure in the valve chamber 16 bv liow fromthe emergency reservoir to a degree slightly exceeding the train pipepressure, the equalizing piston 15 is shifted and the graduating valve19 is moved outwardly to the position shown in Fig. 6 of the drawing, inwhich the port 74 is blanked, and in which cavity 75 connects port '76with a port 86 registering with passage 2- Fluid is thereupon ventedfrom release piston chamber 23 and since passage 26 is now blanked, thefluid pressure in piston chamber 25 operates to shift the release valvedevice so as to close the brake cylinder exhaust. This operation ofreleasing a portion of the fluid from the brake cylinder may be repeatedas desired by making further gradual increases in train pipe pressure,as will be evident. until the emergency reservoir pressure nearlyequalizes with the pressure in valve chamber 16 when the spring 60operates to return the piston 56 to release position and the equalizingvalve parts are free to return to normal release position.

If it is desired to make a full release of the brakes after a serviceapplication, the train pipe pressure is restored to normal pressure.This increase in train pipe pressure forces the equalizing valve devicetoward normal release position but the parts are at first stopped in thegraduated release position by the graduated release piston 56. In thisposition, the feed groove 61 and the emergency reservoir charging port112 are closed, thus preventing train pipe air from .um mmueswna MW...up... .1

flowing either to the auxiliary the emergency reservoir.

Passage 24 is blanked by the graduating valve 19 and passage 26 leadingto release piston chamber 25 is open to the atmosphere through port 74,cavity in the graduating valve 19 and port 76 and cavity 77 in the mainslide valve and exhaust port 73. The release valve device is then forcedto release positio'n by the fluid pressure in piston chamber 23, openingthe service brake cylinder to the exhaust through passage 81, cavity 82and exhaust port 79. I

The first movement of the equalizing pis-' ton 15 toward releaseposition makes connection from valve chamber 16 through port 114 in thegraduating valve 19 and port 115 in the main slide valve 18 .withpassage 116 and as this passage is connected by cavity 82 in the releaseslide valve 22 with exhaust port 79, fluid is vented from the auxiliaryreservoir and a slight reduction in auxiliary reservoir pressure iseffected which insures the prompt movement of the parts to graduatedrelease position and obviates any tendency of the parts to stop beforethe release piston passage 26 is fully open. Emergency reservoir air cannow flow back through port (34 and passages 62 and 17 to the valvecham-' ber 16 and the auxiliary reservoir and when the auxiliaryreservoir has been recharged from the emergency reservoir to within fivepounds of the emergency reservoir pressure, the charging valve 30 isopened by the auxiliary reservoir pressure in chamber 33, permitting theservice reservoir to recharge as hereinbefore described. lVhen thereduction in emergency reservoir pressure thus effected has nearlyequalized the opposing fluid pressures on the graduated release piston56, the same is shifted by its spring 60 to release position, theequalizing piston 15 with the slide valves 18 and 19 following, so thatall the parts are returned to full release position.

In order to illustrate certain features of reservoir or my invention,two brake cylinders are,

shown, although it will be understood that only one brake cylinder needbe employed so far as many features of my invention are concerned.

In order to effect an emergency application of the brakes, a sudden renotion in train pipe. pressure is made, which causes the equalizingvalve parts to be shifted to applicatiop position the same as in serviceand the release valve device to the position closing the brake cvlinderexhaust. In addition. the train pipe pressure reducing to apredetermined degree permits the protection valve device 48 to move outand thereby open communication from passage 47 to an exhaust port 87.Fluid is thereupon vented from the emergency piston chamber 41 and theemergency piston 40 is thus shifted outwardly. According to the presentconstruction, a graduating valve 43 is moved by the initial movement ofthe emergency piston,-

so as to uncover a port 88 in the slide valve 42. Fluid is thereuponsupplied from valve the slide valve 42 is shifted, so that the passage51 is connected by cavity 89 with passage 71. Fluid under pressure inthe closing chamber 7 0' is then supplied to quick action piston chamber50 and this holds the piston in open position until the fluid in theclosing chamber has all escaped through the small port 90in the quickaction piston to the exhaust port 55, the pistonstem 91 being a loosefit to permit such escape. The quick action parts are then moved to theclosed position by the action of spring 92. In emergency position, acavity 93 in emergency slide valve 42 connects passage 94 with anexhaust port 95 and passage 94 is connected by cavity 96 in the releaseslide valve 22 with passage 97 leading to one side of a valve piston 98.Fluid is thus vented from Said valve piston. Before proceeding, it maybe well to explain that in the normal release position of the parts,passage 97 is connected by a port 99 in the release slide valve withvalve chamber 27, so that emergency reservoir fluid is supplied to thevalve piston 98 at one side. The opposite side of the valve piston isopen to the emergency brake cylinder 5 through passage 100 and aspassage 100 is connected by passages 101 and 102 through cavity 93 withexhaust port 95. the emergency brake cylinder as well as the inner-faceof the valve piston 98 is at atmospheric pressure and the pressure onthe opposite side of the valve chamber maintains the valve piston in itsclosed position.

A small emergency port 117 leads from passage 29 to the chamber at theouter face of valve piston 98, so as to insure the maintenance of fluidpressure therein against possible leakage.

In emergency position of the emergency slide valve 42, passage 102 isconnected by port 103 with valve chamber 44, so that the pressure inquick action chamber 45 acts on valve piston 98 and assists in openingthe same. As soon as the valve piston 98 lifts from its seat, fluid fromthe emergency reservoir 9 is supplied through passage 29 to the brakecylinder and also from the service reservoir. 8 through passage 68 pastcheck valve 104. Fluid also flows to the service brake cylinder 3 frompassage 101 past check valve 105 to passage 80. Thus fluid is quicklysupplied through large passages directly to both brake cylinders fromthe service and emergency reservoirs in an emergency application of thebrakes.

In order to assist in maintaining the fluid pressure in the quick actionchamber, a passage 106 leading from passage 26 is uncovered b themovement of the emergency slide valve 42, so that fluid equalizingthrough the equalizing port 78 from valve chamber 27 is supplied to thequick action chamber.

The emergency piston 40 remains in emergency position until the trainipe pressure is increased to release the bra es, the protection valvedevice 48 being then shifted when the train pipe pressure is increasedto a predetermined degree to open communication from the train pipe tothe emergency piston chamber 41. The emergency valve device beingreturned to normal release position, the valve piston 98 is moved to theclosed position and the emergency brake cylinder is connected to exhaustport 95. The equalizing valve device is also shifted to release positionin the .manner hereinbefore described in connection with releasing aftera service application of the brakes.

It may sometimes happen that the graduating valve of the equalizingvalve device will offer more resistance to movement than the main slidevalve and in order to insure that fluid will be supplied to the brakecylinder even if such should be the case, one feature of my inventionconsists in roviding a cavity 107 in. the main slide va ve which isadapted upon movement of the main slide valve to connect brake cylinderpassage 84 with a passage 108 leading to auxiliary reservoir passage 17.Fluid under pressure fromthe auxiliary reservoir is thus supplied to theservice brake cylinder. The movement of the equalizing valve device alsocauses the cavity 77 7 with exhaust port 73, so that the release valvedevice is operated to close the brake cylinder exhaust as beforedescribed. It will now be evident that with the above described feature,an application of the brakes is secured, even if the equalizing pistonshould move the main valve without causing the usual relative movementof the graduating valveto open the usual service port.

It will be noted that action of the graduated release piston 56 inholding the equal izing valve parts at graduated release positionoperates to prevent the recharging of the auxiliary, service, andemergency reservoirs from the train pipe until the emergencyreservoirpressure has nearly equalized with the other reservoirpressures and thus the movement of thee ualizing pistons throughout thetrain to re ease POSltlOIl is insured before any reservoir rechargingtakes place. Thus the graduated release piston may be employed toaccomplish a pur to connect passage 24 pose similar to that of thecharging valve 30, although the latter is preferred as the operation ofsame is not dependent upon a spring.

If it is desired to cut out graduated release, the graduated release cap63 is shifted to the position shown in Fig. 7, in which the emergencyreservoir passage 62 is blanked and the passage 59 is connected bycavity 118 therein with auxiliary reservoir passage 17. As the pressurein chamber 58 is now maintained at the same pressure as that acting onthe opposite side of the piston 56, it will.be evident that the spring60 will hold the iston in the normal release position at al times.

The protection valve 48 operates when the train pipe pressure has beenreduced to a predetermined degree and thus may not operate under suddenreductions in train pipe pressure of slight amount. It is desirable thatan emergency application of the brakes may be secured upon any suddenreduction in train pipe pressure even where the reduction is only threeto five pounds in amount. In order to insure the obtaining an emergencyapplication of the brakes under any sudden reduction in train pipepremure, the-emergency graduating valve 43 is employed. A service rateof reduction in train pipe pressure will not move the emergency piston40, as the capacity of the feed groove 69 is sufficient to provide forsame, but sudden reduction in train pipe pressure exceeding thepredetermined service rate of reduction causes the movement of theemergency piston and since it is only necessary to move the graduatingvalve 43 to initiate quick action, it will be seen that substantiallyany sudden reduction in train pipe pressure even as slight as threepounds will cause quick action and an emergency application of thebrakes.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. In a fluid pressure brake, the combination with a train pipe, of avalve device subject to variations in train pipe pressure and. having anormalrelease position and two other positions, movement between whicheffects the graduated release of the brakes and means for defining thegraduated release position.

2. In a fluid pressure brake, the combination with a train pipe, of avalve device subject to variations in train pipe pressure forcontrolling the release of the brakes and having a normal releaseposition and a position for graduatin t e release of the brakes andmeans or preventing move ment of said valve device from the gradua'tedrelease position to the normal release position.

3. In a fluid pressure brake, the combina- Ill tion with a train pipe,of a valve device subject to variations in train pipe pressure forcontrolling the release of the brakes and having a normal releaseposition and a position for graduating the release of the brakes andmeans operating upon an application of the brakes for defining thegraduated release position.

4. In a fluid pressure brake, the combination with a train pipe, of amain valve controlling the release of the brakes in one position, anauxiliary valve for controlling the release of the brakes in anotherposition, a piston subject to variations in train pipe pressure foroperating said valves, and means operating upon a reduction in trainpipe pressure for defining the release position in which the release iscontrolled by the auxiliary valve.

In a fluid pressure brake, the combina-, tion with a train pipe, of amain valve movable from one release position for effecting the closureof the brake cylinder exhaust, an auxiliary valve movable from anotherposition for effecting the closure of the brake cylinder exhaust, and apiston subject to variations in train pipe pressure for operating saidvalves, and a stop device for temporarily preventing movement of theparts from the second release position to the first.

6. In a fluid pressure brake, the combination With a train pipe, of avalve device comprising a main valve, an auxiliary valve, and a pistonsubject to variations in train pipe pressure for operating said valvesto eflect the release of the brakes, the main valve being adapted toeffect the closure of the brake cylinder exhaust upon movement of saidvalve device from one release position and the auxiliary valve uponmovement from another release position, and means for preventingmovement of the valve parts from the second release position to thefirst.

7. In a fluid pressure brake, the combination with a train pipe, of avalve device for controlling the release of the brakes comprising a mainvalve controlling ports for effecting the release of the brakes in oneposition of the valve device, an auxiliary valve controlling ports forefi'eeting the release of the brakes in another position of the valvedevice, a piston subject to variations in train pipe pressure foroperating said valves, and means operated upon an appllcation of thebrakes to form a stop for limiting the movement of the valve device tothe release position of the auxiliary valve in releasing the brakes.

8. In a fluid pressure brake, the combination with a train pipe, of avalve device subject to variations in train pipe pressure forcontrolling the application and release of the brakes and having twopositions in which the brake cylinder is open to the exhaust and meansoperated upon an application of the brakes to form a stop to limit themovement of said valve device in releasing the brakes to one of saidrelease positions.

9. In a fluid pressure brake, the combination with a train pipe andauxiliary reservoir, of an equalizing valve device subject to theopposing pressures of the train pipe and auxiliary reservoir, forcontrolling the application and release of the brakes and having anormal release position and a piston operated upon a reduction inauxiliary reservoir pressure in applying the brakes for preventing themovement of said equalizing valve device to said normal release positionin releasing the brakes.

10. In a fluid pressure brake, the combination with a train pipe, of anequaliz ing valve device comprising a main valve having a normal releaseposition, an auxiliary valve mounted on the main valve and having amovement relative to the main valve for controlling the release of thebrakes in another position of the main valve, and a piston subject tovariations in train pipe pressure for operating said valves, and meansmovable uponiapplying the brakes to a position for holding the mainvalve in the second release position and for preventing movement of saidvalve to said normal release position upon releasing the brakes.

11. In a fluid pressure brake, the combination with a train pipe, of anequalizing valve device subject to variations in train pipe pressure forcontrolling the brakes, a reservoir adapted to be charged in the normalrelease position of the equalizing valve device, an additional reservoirnormally charged with fluid under pressure, and means for holding saidequalizing valve device in another position for releasing the brakesuntil fluid pressure in said additional reservoir has substantiallyequalized with the fluid pressure in the first mentioned reservoir.

12. ln a fluid pressure brake, the combination with a train pipe, of anequalizing valve device subject to variations in train pipe pressure foreffecting an application of the brakes and a release valve devicecomprising a valve for controlling a brake cylinder exhaust port and apiston having two piston heads for operating said valve, the equalizingvalve device controlling ports for varying the fluid pressure on saidheads.

13. In a fluid pressure brake, the combina tion with a train pipe, of anequalizing valve device .ubject to variations in train pipe pressure foreffecting an application of the brakes and a release valve device comprising a valve for controlling a brake cylinder exhaust port and apiston having two piston heads provided with equalizing ports tending tonormally maintain thefluid pressures equal on opposite sides of saidheads,

the equalizing valve device controlling ports for venting fluid fromeach piston head to thereby operate the release valve device.

14. In a fluid pressure brake, the combination with a train pipe, of anequalizing valve device subject to variations in train pipe pressure, asource of fluid pressure, and a release valve device for controlling therelease of fluid from the brake cylinder, the equalizing valve devicecontrolling ports for varying the pressure on said release valve devicefor operating same to open and close the brake cylinder exhaust and therelease valve device controlling means for venting fluid from the sourceof pressure to one side of the equalizing valve device to operate theequalizing valve device and thereby the release valve device to closethe brake cylinder exhaust.

15. In a fluid pressure brake, the combination with a train pipe, of arelease valve device for controlling the exhaust of fluid from the brakecylinder and an equalizing valve device operated upon an increase intrain pipe pressure for eflecting the movement of said release valvedevice to open the brake cylinder exhaust and means controlled by saidrelease valve device for effecting the movement of the equalizing valvedevice to a movement of the re ease valve device to close said brakecylinder exhaust.

16. In a fluid pressure brake, the combination with a train pipe, of arelease valve device comprising a valve for controlling the release offluid from the brake cylinder, a piston having two iston heads foroperating said valve, sai heads having equalizing ports for permittingequalization of fluid pressures from the chamber intermediate the pistonheads to the iston chambers at the outer faces of said hea s, and anequalizing valve device operated upon a reduction in train pipe pressurefor venting fluid from one piston head to operate the release valvedevice for closing the brake cylinder exhaust and operated upon anincrease in train pipe pressure for venting fluid from the other pistonhead to operate said release valve device for opening the brake cylinderexhaust.

17. In a fluid pressure brake, the combination with a train pipe, of anequalizing valve device com rising a main valve and an auxiliary valveor controlling orts for effecting a service application 0 the brakes anda piston subject to train pipe pressure for operating said valve, themain valve having means for effecting a service a plication of thebrakes independently o the auxiliary valve.

position for causing the.

18. In a fluid pressure brake, the combination with a train pipe, of anequalizing valve device comprising a piston subject to train pipepressure, a main valve and an auxiliary valve having a movement relativeto the main valve and operated by said piston upon a gradual reductionin train pipe pressure for opening a port for effecting an applicationof the brakes, the main valve being also adapted to open a port -foreffecting a service application of the brakes independently of theauxiliary valve.

19. In a fluid pressure brake, the combination with a train pipe, of anemergency valve device comprising a main valve, an auxiliary valvehaving a movement relative to the main valve for effecting an emergencyapplication of the brakes, and a piston operated upon a sudden reductionin train pipe pressure for controlling said valves.

20. In a fluid pressure brake, the combination with a train pipe, ofmeans for effecting an emergency application of the brakes, an emergencyvalve device comprising a main valve, an auxiliary valve having amovement relative to the main valve for controlling said means, and apiston operating upon a sudden reduction in train pipe pressure foroperating said valves.

21. In a fluid pressure brake, the combination with a train pipe, ofmeans for effecting an emergency application of the brakes, an emergencyvalve device comprising a -main valve, an auxiliary valve having amovement relative to the main valve for controlling said means, and apiston adapted upon a sudden reduction in train pipe pressure to firstoperate said auxiliary valve for varying the fluidpressure on said meansto operate the same and then actuate the main valve for maintaining saidmeans in the operative position.

22. In a fluid pressure brake, the combination with a train pipe, of anequalizing valve device comprising a piston subject to train pipepressure, a main valve and an auxiliary valve having a movement relativeto the main valve and operated by said piston upon a gradual reductionin train pipe pressure for effecting a service application of thebrakes, and means controlled by the main valve for effecting a serviceapplication of the brakes upon failure of the auxiliary valve to moverelatively to the main valve.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER. Witnesses:

A. M. CLuMEN'rs, S. W. KEEFER.

